OP is on point. The first season was mediocre. I've seen worse shows, but it felt too much like an average sitcom. Marlon wasn't even that funny.
Season two was better, but it still wasn't there yet. I don't think the show really started finding itself until near the end of the second season. Plus, the recurring characters (White Mike, Lou, Monique, that Jamaican guy) were all
.
Seasons 3-4 were the peak. Most of the classic episodes were during that time. The less restrained Marlon was, the funnier he was. Plus, you can tell Marlon and Shawn were gaining more control because the comedy felt more unique. They weren't just doing standard sitcom jokes.
Season 5 wasn't the best season, but it was still really good. "The High Life" was shyt because they took it seriously when it should have been a parody. Honestly, the show only had one more season left. It wasn't going past 2000, and if it did, the last season would have been shorter like with Jamie Foxx and Steve Harvey.
That's almost always the case. Later Fresh Prince episodes are light years ahead of earlier episodes. I think Martin is the only show that was good and stayed good from the jump.
Fresh Prince was consistently good. Season six was a little weak, but it was the last season so they were coasting.
Most shows start out really good or decent, but then they fall off. Wayans Bros. was an exception in that when it ended, it was undeniably better than it was when it started.